1. Field of Invention
The current invention relates to mesoporous silica nanoparticles, and more particularly to mesoporous silica nanoparticles adapted for biomedical applications.
2. Discussion of Related Art
There has been recent rapid progress in utilizing inorganic nanoparticles for biomedical applications due to the extensive amount of work done in the synthesis and modification of the materials (Georganopoulou, D. G.; Chang, L.; Nam, J.-M.; Thaxton, C. S.; Mufson, E. J.; Klein, W. L.; Mirkin, C. A. Nanoparticle-Based Detection in Cerebral Spinal Fluid of a Soluble Pathogenic Biomarker for Alzheimer's Disease. Proc. Natl. Acad. Sci. USA 2005, 102, 2273-2276; Gao, X.; Cui, Y.; Levenson, R. M.; Chung, L. W. K.; Nie, S. In Vivo Cancer. Targeting and Imaging with Semiconductor Quantum Dots. Nat. Biotechnol. 2004, 22, 969-976; Wu, X.; Liu, H.; Liu, J.; Haley, K. N.; Treadway, J. A.; Larson, J. P.; Ge, N.; Peale, F.; Bruchez, M. P. Immunofluorescent Labeling of Cancer Marker Her2 and Other Cellular Targets with Semiconductor Quantum Dots. Nat. Biotechnol. 2002, 21, 41-46; Lee, J.-H.; Huh, Y.-M.; Jun, Y.-W.; Seo, J.-W.; Jang, J.-T.; Song, H.-T.; Kim, S.; Cho, E.-J.; Yoon, H.-G.; Suh, J.-S. et al. Artificially Engineered Magnetic Nanoparticles for Ultra-Sensitive Molecular Imaging. Nat. Med. 2007, 13, 95-99; Na, H. B.; Lee, J. H.; An, K.; Park, Y. I.; Park, M.; Lee, I. S.; Nam, D.-H.; Kim, S. T.; Kim, S.-H.; Kim, S.-W. et al. Development of a T1 Contrast Agent for Magnetic Resonance Imaging Using MnO Nanoparticles. Angew. Chem., Int. Ed. 2007, 46, 5397-5401; Slowing, I. I.; Trewyn, B. G.; Lin, V. S.-Y. Mesoporous Silica Nanoparticles for Intracellular Delivery of Membrane-Impermeable Proteins. J. Am. Chem. Soc. 2007, 129, 8845-8849). These nano-sized materials provide a robust framework in which two or more components can be incorporated to give multifunctional capabilities. An example can be seen in gold nanomaterials: the ability to control the size and shape of the particles and their surface conjugation with antibodies allow for both selective imaging and photothermal killing of cancer cells by using light with longer wavelengths for tissue penetration (Huang, X.; El-Sayed, I. H.; Qian, W.; El-Sayed, M. A. Cancer Cell Imaging and Photothermal Therapy in the Near-Infrared Region by Using Gold Nanorods. J. Am. Chem. Soc. 2006, 128, 2115-2120; Chen, J.; Wang, D.; Xi, J.; Au, L.; Siekkinen, A.; Warsen, A.; Li, Z. Y.; Zhang, H.; Xia, Y.; Li, X. Immuno Gold Nanocages with Tailored Optical Properties for Targeted Photothermal Destruction of Cancer Cells. Nano Lett. 2007, 7, 1318-1322; Gobin, A. M.; Lee, M. H.; Halas, N. J.; James, W. D.; Drezek, R. A.; West, J. L. Near-Infrared Resonant Nanoshells for Combined Optical Imaging and Photothermal Cancer Therapy. Nano Lett. 2007, 7, 1929-1934). Similar success was also demonstrated with polymer-coated superparamagnetic iron oxide nanoparticles. By conjugating multiple components such as fluorescent molecules, tumor-targeting moieties, anticancer drugs, or siRNA to the polymeric coating, not only can these multifunctional nanoparticles target human cancers, they can also be imaged inside the body by both magnetic resonance (MR) and fluorescence imaging (Kohler, N.; Sun, C.; Fichtenholtz, A.; Gunn, J.; Fang, C.; Zhang, M. Methotrexate-Immobilized Poly(ethylene glycol) Magnetic Nanoparticles for MR Imaging and Drug Delivery. Small 2006, 2, 785-792; Medarova, Z.; Pham, W.; Farrar, C.; Petkova, V.; Moore, A. In Vivo Imaging of siRNA Delivery and Silencing in Tumors. Nat. Med. 2007 13, 372-377). The capability to simultaneously image and treat tumors with nanoparticles may prove advantageous over conventional chemotherapy. Therefore, there is thus a need for improved nanoparticles for use in biological systems.